library(texreg)
# First, create a class definition for your regression objects. Let's call them "MI":
setClass(Class="MI", 
         representation=representation(names="character",
                                       coef="numeric",
                                       se="numeric",
                                       pval="numeric",
                                       n="numeric",
                                       aic="numeric")
         )
# Next, create a constructor that allows you to create new objects:
MI <- function(names, coef, se, pval, n, aic) {
  new("MI", names=names, coef=coef, se=se, pval=pval, n=n, aic=aic)
}

# Then write an extension that translates MI objects into texreg objects:
extract.MI <- function(model) {
  tr <- createTexreg(
    coef.names=model@names, 
    coef=model@coef, 
    se=model@se, 
    pvalues=model@pval, 
    gof.names=c("Num obs.","AIC"), 
    gof=c(model@n, model@aic), 
    gof.decimal=c(FALSE,TRUE)
  )
  return(tr)
}

# Tell texreg that this extension should actually be used for william objects:
setMethod("extract", signature=className("MI"), 
          definition = extract.MI)